Early-stage detection and identification of malignant pulmonary nodules can allow proper medication and increase the survival rate of lung cancer patients. High-Resolution Computed Tomography (HRCT) ...image slices are in use for the screening of lung cancer. However, appropriate identification of lung nodules at the early stage of the disease is challenging owing to similar morphological properties of benign and malignant nodules. Introduction of computer vision and advanced image analysis techniques for the development of Computer-aided diagnosis (CADx) systems have significantly improved the classification performance and increase the speed the interpreting lung CT images for the identification of lung cancer. Deep learning-based techniques have recently emerged as an efficient tool for the improved characterization of lung nodules. In this research work, a deep learning (DL) based framework has been introduced using the concept of adaptive morphology-based operations combined with Gabor filter (GF) for accurate lung nodule classification. The new framework, 2-Pathway Morphology-based Convolutional Neural Network (2PMorphCNN) with its two trainable paths can capture both textural and morphological features of the lung nodules that results in better classification accuracy. The proposed system has been trained and evaluated on LIDC-IDRI dataset and achieved sensitivity, specificity, accuracy of 96.85%, 95.17%, and 96.10% with an Area under the ROC Curve (AUC) of 0.9936 for lung nodule characterization. It has been observed that the reported automatic lung nodule classification framework outperforms other state-of-the-art nodule classification methodologies by capturing and combining textural and morphological features from the HRCT lung nodule image.
Terrestrial animals and robots are susceptible to flipping-over during rapid locomotion in complex terrains. However, small robots are less capable of self-righting from an upside-down orientation ...compared to small animals like insects. Inspired by the winged discoid cockroach, we designed a new robot that opens its wings to self-right by pushing against the ground. We used this robot to systematically test how self-righting performance depends on wing opening magnitude, speed, and asymmetry, and modeled how kinematic and energetic requirements depend on wing shape and body/wing mass distribution. We discovered that the robot self-rights dynamically using kinetic energy to overcome potential energy barriers, that larger and faster symmetric wing opening increases self-righting performance, and that opening wings asymmetrically increases righting probability when wing opening is small. Our results suggested that the discoid cockroach's winged self-righting is a dynamic maneuver. While the thin, lightweight wings of the discoid cockroach and our robot are energetically sub-optimal for self-righting compared to tall, heavy ones, their ability to open wings saves them substantial energy compared to if they had static shells. Analogous to biological exaptations, our study provided a proof-of-concept for terrestrial robots to use existing morphology in novel ways to overcome new locomotor challenges.
This paper uses adaptive morphology to construct an adaptive elliptic structure element that changes adaptively according to the image’s local neighborhood information. To calculate convolution, a ...Gaussian kernel with the outer product of the image gradient is used to achieve the diffusion of the linear matrix values of the initial matrix. The spatial distance of the pixels determines the size of the structural elements, and the pixel points that do not exceed the threshold are selected. The adaptive morphology method resulted in a 27.7 difficulty level for visual communication design, and the algorithm’s accuracy was 87.18%. Advertising design can break through dimensional limitations in visual space through adaptive morphology to generate interaction, indicating a path for development.
This article takes a step to provide humanoid robots with adaptive morphology abilities. We present a systematic approach for enabling robotic covers to morph their shape, with an overall size ...fitting the anthropometric dimensions of a humanoid robot. More precisely, we present a cover concept consisting of two main components: a skeleton , which is a repetition of a basic element called node , and a soft membrane , which encloses the cover and deforms with its motion. This article focuses on the cover skeleton and addresses the challenging problems of node design, system modeling, motor positioning, and control design of the morphing system. The cover modeling focuses on kinematics, and a systematic approach for defining the system kinematic constraints is presented. Then, we apply genetic algorithms to find the motor locations so that the morphing cover is fully actuated. Finally, we present control algorithms that allow the cover to morph into a time-varying shape. The entire approach is validated by performing kinematic simulations with four different covers of square dimensions and having <inline-formula><tex-math notation="LaTeX">3\times 3</tex-math></inline-formula>, <inline-formula><tex-math notation="LaTeX">4\times 8</tex-math></inline-formula>, <inline-formula><tex-math notation="LaTeX">8\times 8</tex-math></inline-formula>, and <inline-formula><tex-math notation="LaTeX">20\times 20</tex-math></inline-formula> nodes, respectively. For each cover, we apply the genetic algorithms to choose the motor locations and perform simulations for tracking a desired shape. The simulation results show that the presented approach ensures the covers to track a desired shape with good tracking performances.
Five major taxa of shrimp-like eucarid are recognized: the order Euphausiacea, the suborder Dendrobranchiata, and three infraorders of the suborder Pleocyemata (Caridea, Procarididea, and ...Stenopodidea). These animals are very successful in the colonization of the pelagic but the role of the sexual structures (the appendix masculina and the petasma) in this process remains uncertain. We revise the vertical distribution of pelagic species and genera within the shrimp-like eucarids and the presence and types of the male copulatory organs. We further test the hypothesis that the pelagic habitat is associated with the elaborated male copulatory organs and discuss possible mechanisms of association. We also consider possible effects of the depth and coastal factors. In the turbulent and fluid pelagic, successful copulation depends on the perfect fixation and possible stimulation of mates during spermatophore transfer and thus on the development and elaboration of the copulatory structures. The presence of the appendix masculina is necessary for copulation in the pelagic and thus for colonization of the pelagic. The ‘family success’ in colonizing the pelagic depends on the presence of the elaborate petasma, whilst the ‘species success’ is not so obviously related to the presence of this organ. The colonization of the water column by the eucarids may basically occur at the family level and be associated with the elaboration of the petasma. Within monophyletic pelagic groups, a greater development of the petasma is observed in the epi- and mesopelagic; some reduction of this organ in the bathypelagic may be related to the reduction in current velocities and turbulence. Simplification of the petasma is also observed in coastal waters. The proposed hypothesis is invariant to phylogenetic models and suggests an explanation to why (but not in which consequence) the elaborated copulative organs have been developed/retained in the pelagic or reduced/lost in the benthic.
•An improved lung segmentation algorithm is presented employing morphological techniques.•Considering the morphological and deformable properties of the lung nodules, adaptive structuring elements ...have been introduced for the development of morphological filters.•Gray scale adaptive morphological filters are developed for the segmentation and detection of large varieties of candidate nodules.
Lung cancer is one of the most life-threatening cancers mostly indicated by the presence of nodules in the lung. Doctors and radiological experts use High-Resolution Computed Tomography (HRCT) images for nodule detection and further decision making from visual inspection. Manual detection of lung nodules is a time-consuming process. Therefore, Computer-aided detection (CADe) systems have been developed for accurate nodule detection and segmentation. CADe-based systems assist radiologists to detect lung nodules with greater confidence and a lesser amount of time and have a significant impact on the accurate, uniform, and early-stage diagnosis of lung cancer. In this research work, an adaptive morphology-based segmentation technique (AMST) has been introduced by designing an adaptive morphological filter for improved segmentation of the lung nodule region. The adaptive morphological filter detects candidate nodule regions by employing adaptive structuring element (ASE) and at the same time improves nodule detection accuracy by reducing false positives (FPs) from the Computed Tomography (CT) slices. The detected nodule candidate regions are then processed for feature extraction. In this study, morphological, texture and intensity-based features have been used with support vector machine (SVM) classifier for lung nodule detection. The performance of the proposed framework has been evaluated by incorporating a 10-fold cross-validation technique on Lung Image Database Consortium-Image Database Resource Initiative (LIDC/IDRI) dataset and on a private dataset, collected from a consultant radiologist. It has been observed that the proposed automated computer-aided detection system has achieved overall classification performance indices with 94.88% sensitivity, 93.45% specificity and 94.27% detection accuracy with 1.8 FPs/scan on LIDC/IDRI dataset and 91.43% sensitivity, 90.45% specificity, 92.83% accuracy with 3.2 FPs/scan on a private dataset. The results show that the proposed CADe system presented in this paper outperforms the other state-of-the-art methods for automatic nodule detection from the HRCT image.
This paper addresses the formulation of adaptive morphological filters based on spatially-variant structuring elements. The adaptivity of these filters is achieved by modifying the shape and ...orientation of the structuring elements according to a multiple orientation vector field. This vector field is provided by means of a bank of directional openings which can take into account the possible multiple orientations of the contours in the image. After reviewing and formalizing the definition of the spatially-variant dilation, erosion, opening and closing, the proposed structuring elements are described. These spatially-variant structuring elements are based on ellipses which vary over the image domain adapting locally their orientation according to the multiple orientation vector field and their shape (the eccentricity of the ellipses) according to the distance to relevant contours of the objects. The proposed adaptive morphological filters are used on gray-level images and are compared with spatially-invariant filters, with spatially-variant filters based on a single orientation vector field, and with adaptive morphological bilateral filters. Results show that the morphological filters based on a multiple orientation vector field are more adept at enhancing and preserving structures which contains more than one orientation.
The salinity barrier that separates marine and freshwater biomes is probably the most important division in biodiversity on Earth. Those organisms that successfully performed this transition had ...access to new ecosystems while undergoing changes in selective pressure, which often led to major shifts in diversification rates. While these transitions have been extensively investigated in animals, the tempo, mode, and outcome of crossing the salinity barrier have been scarcely studied in other eukaryotes. Here, we reconstructed the evolutionary history of the species complex Cyphoderia ampulla (Euglyphida: Cercozoa: Rhizaria) based on DNA sequences from the nuclear SSU rRNA gene and the mitochondrial cytochrome oxidase subunit I gene, obtained from publicly available environmental DNA data (GeneBank, EukBank) and isolated organisms. A tree calibrated with euglyphid fossils showed that four independent transitions towards freshwater systems occurred from the mid‐Miocene onwards, coincident with important fluctuations in sea level. Ancestral trait reconstructions indicated that the whole family Cyphoderiidae had a marine origin and suggest that ancestors of the freshwater forms were euryhaline and lived in environments with fluctuating salinity. Diversification rates did not show any obvious increase concomitant with ecological transitions, but morphometric analyses indicated that species increased in size and homogenized their morphology after colonizing the new environments. This suggests adaptation to changes in selective pressure exerted by life in freshwater sediments.
Recently, transformable Unmanned Aerial Vehicles (UAVs) have become a subject of great interest in the field of flying systems, due to their maneuverability, agility and morphological capacities. ...They can be used for specific missions and in more congested spaces. Moreover, this novel class of UAVs is considered as a viable solution for providing flying robots with specific and versatile functionalities. In this paper, we propose (i) a new design of a transformable quadrotor with (ii) generic modeling and (iii) adaptive control strategy. The proposed UAV is able to change its flight configuration by rotating its four arms independently around a central body, thanks to its adaptive geometry. To simplify and lighten the prototype, a simple mechanism with a light mechanical structure is proposed. Since the Center of Gravity (CoG) of the UAV moves according to the desired morphology of the system, a variation of the inertia and the allocation matrix occurs instantly. These dynamics parameters play an important role in the system control and its stability, representing a key difference compared with the classic quadrotor. Thus, a new generic model is developed, taking into account all these variations together with aerodynamic effects. To validate this model and ensure the stability of the designed UAV, an adaptive backstepping control strategy based on the change in the flight configuration is applied. MATLAB simulations are provided to evaluate and illustrate the performance and efficiency of the proposed controller. Finally, some experimental tests are presented.
Anolis lizards have evolved morphologies in response to different selective factors related to microhabitat use. Morphological diversity exhibits evolutionary patterns that reveal similarities and ...unique regional traits among the mainland and island environments and among Greater Antilles and Lesser Antilles islands. In the Greater Antilles and mainland environments anole species are classified into morphological/ecological groups, that are known as morphotypes (mainland) or ecomorphs (Greater Antilles). Morphotypes are defined only with morphological information; in contrast, for ecomorph assignment both morphology and ethology are required. For mainland species distributed in northwestern South America 10 morphotypes were proposed to include the morphological diversity of 59 species. We obtained data from body size, limbs length, tail length, and the number of lamellae for an additional ten species occurring in the same region and assigned them into morphotypes. We also collected data of the claw and toepad diversity of mainland and island Anolis from northwestern South America and compared it to the claw and toepads morphology recorded for the Greater Antilles and Lesser Antilles islands, under a phylogenetic framework. We found new island morphotypes (MT11–MT13) of Anolis from northwestern South America. When comparing claws and toepads morphology among the 13 morphotypes we found that morphological variation of these traits partially corresponds to morphotype groups. For instance, habitat specialist species like Anolis heterodermus, classified in morphotype 4 (MT4), have a characteristic design of broad toepad and reduced claws, and non‐unique design of toepads and claws occurs in morphotypes MT1, MT2, MT5, MT10, and MT13. We also compared claws and toepads of fore and hindlimbs within the same individual, and found that even if limbs show differences in claws and toepads, suggesting that they perform differential biomechanical function, the degree of within individual variation is specific and not related to morphotype assignment. Our data supported the convergent and unique regional evolution among mainland and island anoles, and revealed aspects of correlative evolution of functional traits of claws and toepads that probably are related to minor differences in microhabitat use among mainland and island species, as suggested by previously published literature. Lastly, the evolutionary pattern of morphological diversity of claws and toepads of Anolis in the mainland and island environment supports both unique regional traits and common selective and historical factors that have molded Anolis morphological diversity.
Highly specialized mainland morphotypes in Anolis exhibit a unique pattern of variation of claw and toepads, unlike other morphotypes, with more broad use of the habitat. Traits of claws and toepads did coevolve in an integrated functional pattern, apparently in response to the microhabitat use. Evolutionary patterns of claw and toepad morphology in mainland, Greater Antilles and small island's anoles shows levels of convergence, but also of unique patterns of variation in each region.
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